Hellraiser is completely right, even if you don't think it exists (an ignorant viewpoint to begin with) it doesn't mean you should take up the attitude, "even if it does exist, it won't affect me, so fuck it!"
That's one of the most selfish approaches you can take, and i can't stress this enough, EVEN IF IT DOESN'T EXIST, why not conserver energy/water/fossil fuels (which WILL run out by the way) and try to explore alternative powers, like harnessing solar energy?
Some facts...
1) every academy of science agrees it exists (and don't give me that bullshit that "they're all in on it together to get money" who pays them for saying global warming exists, huh? It's not like they would profit from it, if anything they would be under huge pressure from oil industries NOT to say it exists)
2) only a select few individuals (scientists who know their shit) actually disagree, and they don't even deny global warming is happening, they're just arguing over the causes (humans vs. cattle, that sort of thing).
3) fossil fuels will run out, why not explore solar energy or at least trying cleaning up the environment? if you're against that, then you're basically saying "it won't affect me, fuck my children and grand children, i'll leave my mess for them"